Hold-down structure for sheet-feeding apparatus



June 13, 1967 F. KEDZIERSKI HOLD-DOWN STRUCTURE FOR SHEET-FEEDING APPARATUS Filed May 26, 1965 2 Sheets-Sheet 1 I: Illklll fwmnzor Franz? ffdzz'ers z It orney June 13, 1967 F. KEDZIERSKI HOLDDOWN STRUCTURE FOR SHEET-FEEDING APPARATUS 2 Sheets-Sheet 2 Filed May 26, 1965 f wenioi" flan? Xedzzrskz' United States Patent 3,325,164 HOLD-DOWN STRUCTURE FOR SHEET-FEEDING APPARATUS Frank Kedzicrski, Chicago, Ill., assignor to The Frederick Post Co., Chicago, 11]., a corporation of Illinois Filed May 26, 1965, Ser. No. 459,005 Claims. (Cl. 271-21) The present invention relates to improvements in sheetfeeding mechanism.

In the apparatus described in the copending application of Niccoli Ser. No. 376,788, filed June 2-2, 1964, and now Patent Number 3,279,787, a stack of sheets is positioned for removal of the top sheet and forward feeding of it partially from the stack to a position of rest awaiting demand for forward advance away from the stack. The sheet is held down at its rear by a weighted rotary roll. The movement of the sheet is effected by means of a friction roller, which first moves the forward portion of the sheet rearwardly toward the hold-down roll, thus forming a hump ahead of the hold-down roll. The hump closes an electrical switch which effects reversal of the rotation of the friction roller and hence forward feed of the sheet, with pull from under the hold-down roll, which is free to turn.

In said apparatus, the hold-down roll is shown as two heavy rollers rigid on a shaft free to turn by pulling the top sheet from under it.

It is the object of the present invention to provide an improved hold-down roll and mounting means therefor.

Various other and ancillary objects and advantages of the invention will appear from the following description of an exemplary form of the invention as shown in the accompanying drawings, in which:

FIG. 1 is a plan view of a portion of a sheet-feeding means showing an upwardly swingable structure on which a second upwardly swingable structure is mounted as a carrier of the improved hold-down roll.

FIG. 2 is a vertical cross section taken on line 2-2 of FIG. 1, showing additional apparatus not illustrated in FIG. 1.

FIG. 3 is a detail vertical cross-section of a portion of the hold-down roll taken on line 3-3 of FIG. 1.

FIG. 4 is a cross-section on line 4-4 of FIG. 1 showing the indexing means for positioning the hold-down roll.

In FIG. 2, platform holds a stack of sheets 12 of which only the last two are shown, the rear end of the stack being positioned against a back-stop 14. Side plates, such as 16, position the stack 12 laterally. A bar 18 under the stack raises it slightly to aid in hump formation.

In FIG. 2 there is a driving shaft 20 with gear 22 meshing with gear 24 rigid on shaft 26, the latter being shown in FIG. 1. Driving shaft 20 is operated in either direction to rotate shaft 26 in either direction. Shaft 26 bears in a frame (not shown). On shaft 26 is pivoted for upward swinging a frame 27, comprising side plates 28 and 30 and connecting cover plate 32. The frame pivots on shaft 26 at one end. In the other end bears a rotary shaft 34 with friction rollers 36 and 38 rigid thereon. Shafts 26 and 34, respectively, have rigid pulleys 40 and 42 connected by belt 44, thus to drive the friction rollers by shaft 26. The side plates 28 and 30, respectively, carry projecting bars 46 and 48 for weight. The described frame can be raised from its position on the stack 12 as needed.

Side plates 28 and 30 carry intermediate their ends a fixed shaft on which is pivoted one end of a mounting 52 overlying the shaft 34 for a hold-down roll means at the other free end. Mounting 52 has a top plate 54 with side plates such as 56 bearing on shaft 50. Mounting 52 carries an electrical switch 58 operated by formation of a hump 12 (FIG. 2). Hump 12 moves lever 60 pivoted at 62, which moves arm 64 of the switch. Incidentally, the mounting also has a second switch 66 operated by arm 68 when a sheet crumples at its location. Crumpling can result from a failure of the sheet to feed forward over a knife-edge plate 70 which holds down the forward end of the stack. Plate 70 is carried by a plate 72 under platform 10, pivoted at 74. The rearward movement of the top sheet pulls it from under plate 70, then the friction rolls 36-38 advance it over the knife-edge of plate 70, except for possible obstruction by the plate 70 causing it to crumple. The frame 27 swinging on shaft 26 may be raised to remedy the crumpling, and in raising it, the overlying mounting 52 is raised with it by reason of the mounting overlying shaft 34. The mounting 52, however, may be raised independently of the frame 27.

Beneath plate 10 is a switch 76- with an operating arm 78 in contact with the bottom sheet of stack 12. When the stack is depleted the arm 74 operates the switch to stop the mechanism.

The hold-down roll means is carried in a separate U- shaped bracket with top plate 80 on the underside of plate 54 and slidable to adjusted positions, the plates 54 and 80 being held together by rivet'like means 82 in slots 84 in plate 54. The U bracket has side plates 86 and 88, carrying fixed shafts 90 and 92. Freely rotatable on shaft 90 are two heavy rollers 94 and 96 connected by a ratchet wheel 98 between them. A pawl 100 urged against the ratchet permits the rollers 94 and 96 to rotate freely when a sheet is pulled forwardly from under them, but prevents rotation when a sheet is moved rearwardly to form a hump, thereby tending to move rearwardly under the rollers. Thus, the rollers not only hold down the stack, but also prevent movement of a top sheet rearwardly under the rollers.

Means is provided to move and hold the mounting 52 in a selected one of several positions.

On the underside of plate 80 is a weld nut (FIG. 4) 102 into which is threaded a screw 104 having a hollow in which is housed a spring 106 pressing a ball 108 into one of a series of holes 110 in plate 54.

The invention is not limited to the illustrative details shown in the drawings, and other constructions are contemplated as falling within the scope of the appended claims.

I claim:

1. In sheet-feeding apparatus means to position a stack of like-sized sheets of paper, friction roll means normally resting on said stack to move the top sheet, means to rotate the friction roll means in both directions while resting on said sheet, hold-down means normally resting on said sheet at a location rearwardly of the stack from said friction roll means, whereby rearward movement of the top sheet by said friction roll means tends to form a hump in said sheet between the friction roll means and said hold-down means, said hold-down means comprising weighted roll means freely rotatable by and With a forwardly feeding sheet, and means to prevent rotation of said weighted roll means in the opposite direction when a bump is forming in the sheet.

2. Apparatus according to claim 1 in which said rotation-preventing means consists of a pawl and ratchet.

3. In sheet-feeding apparatus means to position a stack of likesized sheets of paper, friction roll means normally resting on said stack to move the top sheet, means to rotate the friction roll means in both directions while resting on said sheet, hold-down means normally resting on said sheet at a location rearwardly of the stack from said friction roll means, whereby rearward movement of the top sheet by said friction roll means tends to form a hump in said sheet between the friction roll means and said hold-down means, mounting means for said holddown means, said mounting means extending forwardly from said hold-down means and being horizontally pivoted forwardly of said hold-down means for swinging said mounting upwardly, said hold-down means comprising weighted roll means freely rotatable by and with a forwardly feeding sheet, and means to prevent rotation of said weighted roll means in the opposite direction when a hump is forming in the sheet.

4. In sheet-feeding apparatus means to position a stack of like-sized sheets of paper, friction roll means normally resting on said stack to move the top sheet, mounting means for said friction roll means, said mounting means beinghorizontally pivoted forwardly of said friction roll means for swinging said friction roll means upwardly and away from said stack, means to rotate the friction roll means in both directions while resting on said sheet, hold-down means normally resting on said sheet at a location rearwardly of the stack from said friction roll means, whereby rearward movement of the top sheet by said friction roll means tends to form a hump in said sheet between the friction roll means and said hold-down means, mounting means for said hold-down means, said mounting means extending forwardly from said hold-down means and being horizontally pivoted forwardly of said hold-down means in said first-mentioned mounting means for the friction roll means, forwardly of the friction roll means and rearwardly of the pivoted axis of said first-mentioned mounting means.

5. In sheet-feeding apparatus means to position a stack of like-sized sheets of paper, friction roll means normally resting on said stack to move the top sheet, a horizontally pivoted frame having its axis forward of said friction roll means, said friction roll means being carried by said frame, hold-down roll means normally resting on said sheet at a location rearwardly of said friction roll means, a mounting for said hold-down roll means, said mounting being horizontally pivoted to said frame on an axis rearwardly of the axis of the frame and forwardly of the friction roll means, the rear portion of said frame underlying said mounting, whereby said mounting is swingable upwardly with and by said frame and swingable upwardly independently of said frame.

References Cited UNITED STATES PATENTS 356,784 2/1887 Pritchard 221259 X 363.379 5/1887 Flint 221259 X 469,366 2/1892 SedgWick 271--21 2,165,232 7/1939 Curtis 271-22 2,569,692 10/1951 Rockwell 27121 X 3,279,787 10/1966 Niccoli 271-57 M. HENSON WOOD, ]R., Primary Examiner,

J. N. ERLICH, Assistant Examiner. 

1. IN SHEET-FEEDING APPARATUS MEANS TO POSITION A STACK OF LIKE-SIZED SHEETS OF PAPER, FRICTION ROLL MEANS NORMALLY RESTING ON SAID STACK TO MOVE THE TOP SHEET, MEANS TO ROTATE THE FRICTION ROLL MEANS IN BOTH DIRECTIONS WHILE RESTING ON SAID SHEET, HOLD-DOWN MEANS NORMALLY RESTING ON SAID SHEET AT A LOCATION REARWARDLY OF THE STACK FROM SAID FRICTION ROLL MEANS, WHEREBY REARWARD MOVEMENT OF THE TOP SHEET BY SAID FRICTION ROLL MEANS TENDS TO FORM A HUMP IN SAID SHEET BETWEEN THE FRICTION ROLL 